diff --git a/README.md b/README.md
index 3178898..4354565 100644
--- a/README.md
+++ b/README.md
@@ -44,9 +44,10 @@ and if you do run into problems, email me at
 personally on Gmail, Teknik.io, cock.li and Yandex, while others have tried
 other providers.
 
-One email provider which I think will *not* work (and will never work) is
-Proton Mail, but that's only because they require encryption through their web
-client IIRC.
+If you have a ProtonMail account, due to their secure setup, you must have
+[ProtonMail Bridge](https://protonmail.com/bridge/) installed and configured.
+Compatibility with ProtonMail is still in testing, so be sure to open an issue
+if you have problems as I do not have a paid account to test this with.
 
 Note also that Gmail and some providers require you to enable sign-ins from
 third-party (or as they call it "less secure") applications to be able to load
diff --git a/autoconf/domains.csv b/autoconf/domains.csv
index 4c1a0e1..c27ba52 100644
--- a/autoconf/domains.csv
+++ b/autoconf/domains.csv
@@ -117,6 +117,8 @@ paranoici.org,mail.autistici.org,993,smtp.autistici.org,465
 post.com,imap.mail.com,995,smtp.mail.com,587
 posteo.de,posteo.de,993,posteo.de,587
 privacyrequired.com,mail.autistici.org,993,smtp.autistici.org,465
+protonmail.ch,127.0.0.1,1143,127.0.0.1,1025
+protonmail.com,127.0.0.1,1143,127.0.0.1,1025
 rape.lol,mail.cock.li,993,mail.cock.li,587
 redchan.it,mail.cock.li,993,mail.cock.li,587
 runbox.com,mail.runbox.com,993,mail.runbox.com,587